Are males cheaper than females? Male and female costs of reproduction

In this TIEE experiment, students investigate the costs of reproduction. In dioecious plants, a female's investment in reproduction is typically much greater than a male's, because while both sexes encounter the basic cost to produce a flower, only females have to allocate energy to seeds, exceeding the energy requirements to produce pollen. This 1-2 week field project tests whether the effects of these unequal costs are reflected in characteristics of individuals of functionally dioecious and long-lived Jack-in-the-pulpit (Arisaema triphyllum) in the field. Students will read two introductory articles and take a pre-project online quiz, collect the data in the field, analyze it, collect and interpret literature sources and will write a short report.

This field activity could be used in two ways: (1) in a third-year ecology course for 12-16 undergraduate students using the instructions as outlined in the present document, where students cooperatively collect their data in groups of two, and (2) in third to fourth year, two-week summer field course setting as an individual student project. In the latter setting, the project approach could be more inquiry-based.